Li Xia, Liu Xiangmei, Wu Shuilin, Yeung K W K, Zheng Yufeng, Chu Paul K
Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, Faculty of Materials Science & Engineering, Hubei University, Wuhan 430062, China.
Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, Faculty of Materials Science & Engineering, Hubei University, Wuhan 430062, China.
Acta Biomater. 2016 Nov;45:2-30. doi: 10.1016/j.actbio.2016.09.005. Epub 2016 Sep 6.
The combination of high strength, light weight, and natural biodegradability renders magnesium (Mg)-based alloys promising in orthopedic implants and cardiovascular stents. Being metallic materials, Mg and Mg alloys made for scaffolds provide the necessary mechanical support for tissue healing and cell growth in the early stage, while natural degradation and reabsorption by surrounding tissues in the later stage make an unnecessarily follow-up removal surgery. However, uncontrolled degradation may collapse the scaffolds resulting in premature implant failure, and there has been much research in controlling the degradation rates of Mg alloys. This paper reviews recent progress in the design of novel Mg alloys, surface modification and corrosion mechanisms under different conditions, and describes the effects of the structure, composition, and surface conditions on the degradation behavior in vitro and in vivo.
Owing to their unique mechanical properties, biodegradability, biocompatibility, Mg based biomaterials are becoming the most promising substitutes for tissue regeneration for impaired bone, vascular and other tissues because these scaffolds can provide not only ideal space for the growth and differentiation of seeded cells but also enough strength before the formation of normal tissues. The most important is that these scaffolds can be fully degraded after tissue regeneration, which can satisfy the increasing demand for better biomedical devices and functional tissue engineering biomaterials in the world. However, the rapid degradation rate of these scaffolds restricts the wide application in clinic. This paper reviews recent progress on how to control the degrdation rate based on the relevant corrosion mechanisms through the design of porous structure, phase structure, grains, and amorphous structure as well as surface modification, which will be beneficial to the better understanding and functional design of Mg-based scaffolds for wide clinical applications in tissue reconstruction in near futures.
高强度、轻质和天然生物可降解性的结合使镁（Mg）基合金在骨科植入物和心血管支架方面具有广阔前景。作为金属材料，用于支架的镁及镁合金在早期为组织愈合和细胞生长提供必要的机械支撑，而后期被周围组织自然降解和重吸收则无需进行后续的移除手术。然而，不受控制的降解可能导致支架塌陷，从而导致植入物过早失效，因此在控制镁合金降解速率方面已有很多研究。本文综述了新型镁合金设计、不同条件下的表面改性和腐蚀机制的最新进展，并描述了结构、成分和表面条件对体外和体内降解行为的影响。
由于其独特的机械性能、生物可降解性和生物相容性，镁基生物材料正成为受损骨骼、血管和其他组织组织再生最有前景的替代品，因为这些支架不仅可以为接种细胞的生长和分化提供理想空间，还可以在正常组织形成之前提供足够的强度。最重要的是，这些支架在组织再生后可以完全降解，这可以满足全球对更好的生物医学设备和功能性组织工程生物材料日益增长的需求。然而，这些支架的快速降解速率限制了其在临床上的广泛应用。本文综述了基于相关腐蚀机制，如何通过多孔结构、相结构、晶粒和非晶结构的设计以及表面改性来控制降解速率的最新进展，这将有助于更好地理解和功能性设计镁基支架，以便在不久的将来在组织重建中广泛应用于临床。
